is my filename cause my problem?

veilig · 11-11-2003, 02:59 PM

alright, I'm using linux 9.0 and I'm using the C++ language,

what I need to do is grab input from a user and use that input to open a file.

the way I approached it was to grab the input from the user into a string. (string2)
I then concatenated two strings together to form one string. (string1+=string2)

and when I opened the file I used the command string1.c_str() for the filename.
Fin.open ( string1.c_str(), ios::in );
however, when I'm passing the file to another functions and try to read a line from the file in that function, I get the error message:
Node.cxx:24: invalid use of undefined type `struct std::basic_ifstream<char,
std::char_traits<char> >'
/usr/include/c++/3.2.2/iosfwd:86: declaration of `struct
std::basic_ifstream<char, std::char_traits<char> >'

the line that causes the error is:

Fin.getline ( Kdata, 5, '\n' );

where Fin is the file passed to the function, and Kdata is private data in a record. Kdata is a char array of size 4.
all I'm trying to do is just grab a small line, and put it into

I can't figure out why I'm getting this message, is there a better way to do this,.

megaspaz · 11-11-2003, 07:47 PM

try passing the address of your fstream to your function.

ie.

Code:

int some_func (string, fstream &);

int main ()
{
    fstream in_stream;
    string fname;

   //get the fname blah blah blah
    some_func (fname, in_stream);
    return 0;
}

int some_func (string s, fstream &Fin)
{
    //do your open stuff.
    //return some error code blah blah blah
    return 0;
}

nukkel · 04-22-2006, 10:32 AM

Code:

#include <fstream>